To be clear the Full Version of AC will open EDU files it just switches to EDU mode while the file is open, it will not convert from one to another or let you copy/paste between them.
Since he is a student he can register at myarchicad.com as a student and a free one year EDU license for 15 once he sends proof of status.

I seem to recall that this worked differently a few years ago. FULL and EDU were different versions and different installations.
I am not sure were that changed.
But the Myarchicad.com download is a good idea if he does not need to send back the file to the person he received it from.